1. Technical Field
Embodiments of the present invention relate to a polarizing plate, a composition for protective layers of a polarizing plate, and an optical display including the same.
2. Description of the Related Art
Liquid crystal displays include polarizing plates on both surfaces of a glass substrate, thereby forming a surface of a liquid crystal which displays images on a screen. The polarizing plate includes a polarizer, which is typically manufactured by stretching a polyvinyl alcohol film, and forming a protective film (such as triacetyl cellulose (TAC)) on at least one surface of the polarizer. The protective film is bonded to the polarizer via an adhesive for a polarizing plate. Recently, in order to reduce the thickness of the polarizing plate, a polarizing plate is being developed that includes the protective film on only one surface of the polarizer.
The polarizing plate in which the protective film is formed on only one surface of the polarizer includes an adhesive layer for adhesion to the liquid crystal panel, which is formed on the other surface of the polarizer. However, since the polarizing plate includes the protective film on only one surface of the polarizer, the polarizing plate can suffer from deteriorations in mechanical strength and durability, as compared with polarizing plates in which the protective film is formed on both surfaces of the polarizer. In addition, since the polarizer is manufactured by stretching, the polarizer can suffer from cracking due to shrinkage in the machine direction (MD) (corresponding to a stretching direction thereof) under severe environmental conditions (such as storage or repetitive thermal shock at high temperature and/or high humidity). In particular, the polarizer can suffer from severe cracking along with increased size of the polarizing plate.